ELLA is derived from
HELENA: Greek nameday 21st of may.
HELENA was an empress and equal to the Apostles.
ANNETTA is derived from
ANNA: Greek nameday 9th of december.
ANNA was the mother of the Theotokos (
MARIA).
About Greek namedays:
http://ourworld.compuserve.nl/alexmoundreas/Greek_namedays.com